SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '128ec7f566c6efd0b64200743b42caf7c6f91cd918cd185ba92cfc55068365a2' 
  AND token = 'tLrLMJdYr0oZ7/6unQ15ssTT1Qk90Es1HX6jeaeLhlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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