SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8af8cb2abd348ff4ea84f026c838cfaab5739bef021e489df87809eaab6e4bc' 
  AND token = 'bmmYULbMPn3+gUSz4tEZAZLaZuercHP3RI8y82JRX3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}