SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd4062fc9d77d04ae606f59fbf889329dd05fbbc3da4069f6fb104fdc63a6ef7' 
  AND token = '9hnOmyjdYnkiscygx83cXxgHR+BTp2pCJPOWhBWxYPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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