SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a9ed852ecfc203c2eeef5d899ece698b902a7cf4cf3ffc2bdf0a67523ab50a' 
  AND token = 'q4UmLy70lotYezSAECGZjpSrO0fednhWQEhG4bs4vvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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