SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ca221a0f50ede6333342142f8c31f9b2dfa9d69345c318d319060acb2d3dd57a' 
  AND token = '4yUpbNzRAfUWs5voswx8ibh0hFdDIKzLCrS2aFDBdME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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