SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a3c23ab18ebc71274ac26014a59a1c5e22b64f3fe657541e684078a975df6fd' 
  AND token = 'qKUfPC9Qlop2OhFZdfxLjH5zF46I2St+VvXkulzBXdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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