SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7ed7edea10ca23497be3986fe2160276dafac7a23ffa71d395f35b66e6e28cc' 
  AND token = 'gaW9LuIQzAPplI8W2bmqd1AHFzOCaKw5ViukCVq+Bh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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