SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a6a8a46991bdf4e7fd111c682918b6d792fbcd3eae23da2036e23b4227e2cb1' 
  AND token = 'DMMCCuoX+Qv5WrqsMguZ22WBV/liurtGHGhAtNBA/tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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