SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00e4b0bce55f5159994e91a19f4a0387caa13a619e5b431b758d172e8a4406ef' 
  AND token = 'R76lQvydRaX589RpdFqxR0BXyUU1r2QhuZNFyIRBcCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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