SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b1dd6a82069c539c95be021b92fca421ef4ec71418fa66183ba67f914b2052f' 
  AND token = 'ViUri2ZwBEVxN//8y+iLd18r9D3ruj+ztmwPdm511hA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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