SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54fc10d0b1826acdbd7ef5318d1be6af454cfb84ef6ca408c174b29b86755efd' 
  AND token = 'HFpbnwQOYvY4Wuefb0aqof7HJJigTGvxJ08Q3SPp8tE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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