SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b869cd1cc767219a3e41ad71391bb2c951d3d305c563b4d54d8b865aa1f0da1' 
  AND token = 'JWt8BCZhoucb3DXFhbZPXAL5wAMutVsmUL5QtNeh86k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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