SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d7018f7de97b4c46121dac9691a3f7d650bae784827b458b1d9c7cacac19a4a' 
  AND token = 'Poc0lyiF88WaZiOPK/xIPVtIM+v/jl0QOdbzXfE1nVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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