SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e37fea17a868fde5f5e4bfdbbf2dbe4b63af48c56a882a89bb8485dd91c373f6' 
  AND token = '8jbIiFz/vsoJ1HKQ7AuEtHDsVYQ257mfjyhbwggHSgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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