SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f194c5ef42ab425d950f515aa8c377a7fa3313b9fcad7a94f8fe1067bc0b926d' 
  AND token = '3G1iF+ONlK/Bd//Gd4y+sjkHWY756DcyETcvpmXwl7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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