SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e53875f3a15d7be85ef9fd8f5596628b03fbec115517b06de973e31a2a40a9b' 
  AND token = 'gNyY1Z7GBpqqcYBCOWOMsUSoswlPKWEVkTjWtrlrKFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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