SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab011b26cea4ea9d2723eeefb41324e97626d91d51cb584c3affce12d2a02bab' 
  AND token = '5X8x2GB4W3TQ/8py7AHQtFDXrz4Ilw4c2I9+N3rAtJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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