SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cedae3e058d2120e3d46a45d08c7b54878e32a14c1105490084dc224109e80b7' 
  AND token = '5/98BBh1gVVRHv26jNbDyPNomRV0OiafRXZ8ib2/gNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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