SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f8335c5f79551982058456adda37f407c1b988ae7f4ce51a5a6685f2b4dc3fa' 
  AND token = '071B0EgwrM351EZYoyziBOJ3mAtHG/3B2CvqcBhT4WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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