SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93ac0703903fd5073151f4778dbf67fca2d580e29d1ace8f62dc47c074bcf358' 
  AND token = 'nW/z5/O+Dv0UJkbiw2rbkYPakmgCGm6rXmo3qVTjDO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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