SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87f1a200d105c735f41a5d64d943f6308ef763bc453fa972efb351ec69f83d0b' 
  AND token = 'OQd7DxXK3y5ekDNijJILcbhEqdIjdmFzeRGrn8jnoBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}