SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb13c06b3e31404cbf53f0e960ec3574c262d8e67efc1449609e7d7e28673e6e' 
  AND token = 'QfCyshxbhumGO6JKhYiWS/g++oIFUVRg+bR1bzAqnys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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