SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5c4d1a347b5d32974062a14370c7b9c67d4eabe2a731e7cbfbfe4c7d72757e5' 
  AND token = 'PnyHeK6ZZ61jp8JI9Nv5LlaRzYo/sZ18OAuDQt6fAFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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