SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fd066e6c7bbce2df9258a13460f497cf66e2fc43ccfd740d223f0caf8b30480' 
  AND token = 'zNf7eMb7/rZvbtmpU8wVJuIQ63BbN5y6s6eLfWHI4hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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