SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33350c01b43fea1259a7b0b10b9e809365c15f46d4444a51baf76532b0d54ed7' 
  AND token = 'luuz3qGwkyCosW0gv6GU1zugjZGhhhUfiXvBSB45zEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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