SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4a0733c60100a31e1a2f3bc62c4107740be79a9ec36fb52e29c6c8e413b051b' 
  AND token = 'nq/jR/lVnWrF8+HApeBuLTV0GR4ksTVGpfFz/l8gWoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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