SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e5a3f1a898aa9f3cb386d56780870f17906525109a851a8b3b33ba5abd6fda' 
  AND token = 'FaLh/US9RhFVQLExThzKiC1Rik29P0HWyG/XeBEB2fA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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