SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fead2131a2b3060fcbe1cdb1e2a57f0710bd7b393032c0b42ed14748c9c1c55e' 
  AND token = 'tdjSezyXnvZSeTCx7cTjG3FJAR/I2B1G0cCVlAvF7Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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