SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83b6dbc9b398c82f96612c83294b1bf9c311bea243e4659d179a87e9f895966c' 
  AND token = 'JYPi+gNhzwz/BmpSUnZW2SBUAr12k3a/TGo9taU839w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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