SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d45ef9c01761f905b0e7de633cb440455635aaa419d4ad1d5f704901f5946f0' 
  AND token = 'XDKQCXT4GPB8laMFEiuZuw6nEpunsT1EflSQE74iCJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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