SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60e5f77acc64f3bea7dd09a877e3f304719483d5dc4c6b281e6f93a17fbab108' 
  AND token = 'PHlajBVUi/STfWajmSjOh+4vFvM4d2giKLa75gezEnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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