SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e24f82b4d898e22c0fcde4e54ec5d83ff9daabcef27b42b2858d32927a65c438' 
  AND token = 'oz1JZVY2JIVVw6Y1DLIFopkVy4AcIW5IC0VKG+mHPXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}