SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b84b33890adb78b32e57c4875ec83d47d40e107f524f7a3b079bed2209cb635' 
  AND token = '7rz8YwEB+CIXVQiIjaZvurn8zg7yHYBkhiQmFQbSgSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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