SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc2fa3cb9092309c1dd364d23ac12144084d6bc42ea47d0a9bff5a8c7a22634b' 
  AND token = 'F4Ibq96qZaA1QBBFnGnwUcrgrNAPjGwuBZOVCxXombY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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