SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27cf88e19a4e540c0d5a0dd39030d4e72fda3b5bf4178562eaa263c3de985e59' 
  AND token = 'KCmc101XFjgy8UAO/I0+Ahh1WkCavCeBmRdYypCrWOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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