SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dccef56eb3deab6c889c53c963fa4310f1b9a155abb1d2499de523c70a0f5c3d' 
  AND token = 'gDwQHzGBKoDqo/r5G+SVhwjLTIq3sDwACiQlLbW6JQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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