SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88c591a2f3b4dc4173553fbca709f6de52d3fb5dfbdda968331fdeaf6e09fddb' 
  AND token = 'LqfoxZIzzTnBeCKSPdgwLUdfttrxkxEDjtqINYfbkuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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