SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec6e77e7626d50aa7053022b8f1071149925c033748001ad6e867df492bd0d32' 
  AND token = '3kLPRz17o4ufVmMeWvv7dyH1hqxjAQCBBswVzmwl5dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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