SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f4d72257390992261836d181b0fe6bbe0e4f30d900cec316bec266d5f15e98e' 
  AND token = 'ooQdLDeCqD6Nstzde4lJf+JeVUj2x7omkFmkcHt4N0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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