SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e354403922000ae49317e1c41592763c7174d99f062aaaece5bbf77c9bc91d6' 
  AND token = 'fo+C0qDClyU5HdkNqDYIIBNtEfV1jhrYYw3WfEECQyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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