SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cde71691ef58600ce1b1b59ce5df480e412d1254847d612d7601ae35fca16aa7' 
  AND token = 'SShm5dvNAaDkMI0P2abm1BWZqhlk3uSuwDBEKgV/gJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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