SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f0f5ed7922af9a029fad03d27ee8e572ccc50db62699a397b5801f419da3c6f' 
  AND token = 'EpNIskVW5y+9tGSp9tLkFx51Od3NusZDkqZ9E4QM0vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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