SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2454ada763bef862e8eec4deeb87b10d2f81942b3ecc15cd8aacb5e1f1913d5a' 
  AND token = 'gy1mUGfSCbdgK4avRfqDsko71l1eS92qU287M7Nr59Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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