SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44aa1748a4c7b9fe551f77cdbd10f3aee4320115421ba86bbac146803b68ca39' 
  AND token = 'yuGnX+j9O4VTSZ0SjdOVpn61sXMDGy2Lj9EIcZOZUXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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