SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8996bd1c8ae14114fcb5b869d8b37173d5b8d7d09425b236c60454b0d43948f5' 
  AND token = 'X+Hg1En03rmNzBsIbBXLQ7FlJJDGHBE2B+IuYt1nWQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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