SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f84bb45a2b436da46c4d7e4e6725454f078d151c94dcd2542d1ae8d133876c7' 
  AND token = 'r6vGTZPLYASA7KIIUY31OlS/DVRD/+mNzExGEmXh4xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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