SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b881a0349e669e5283fbffd8850464ada30f7e14d7d8589a71c32462e84794c1' 
  AND token = 'uxh9lk0Jd7en4PF0QAeHR7yUBSOH2s5pU7KFENO7IP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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