SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cf1e2227f169876eb4d67c03952bfc6514979f84c3ef46c9a27f4c2d8f6a596' 
  AND token = 'J5a3q8V91jRW7fKIWmPI+Otw5CkFnXnahoEG+YRqCPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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