SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b28f999248cd3de43af0b3eef1c60a8789ed0d60ac1d9cb875fe77796a980b3c' 
  AND token = 'ZXVZCmq45rDNaCoLDuVYPWOv/0I+BGbptPLRChmGZk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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