SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0ecab2bd99bf203dac1cc97b74fc1ee4eda31d2e94d924b0797f52d808ef5e' 
  AND token = 'GJmYI5uU8GpTPuRhB5cYCuuD6X1VHNIWMOSAq/F7V9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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