SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dba41d2215788ba58ef4513d29d94dceb0864587748d712786b00c6c896e9194' 
  AND token = 'uXauV6JftYHt8qskHIYKPF6v3SgC+NmS+yOgnWfCxeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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