SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd8c6edd2756959f968c6681c273b3ab20448366be195854578b35d830972e46a' 
  AND token = 'CcpGuKASF0Q9LVE45wYjGJcmGn6z7TyZOBXIvLyM1hI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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