SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '056e779d711e6dc38e6b1ca20bc3bbef612ee1e9482d1aff07f0ada6d1a3c94c' 
  AND token = 'CT9elVdzZgqTdwkx/lqSSnzoKGd+DbX2/OiXM+iRo34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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