SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63ba4e5aba8dc2d984cf0b2be957b80d1d8fee2e67d6c8c64e71111b4a0db725' 
  AND token = 'FPrCxGJIhGKIV7+gsQYhzKPONpktAVG6YyGIiJxow0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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