SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87272e3de2363bb1c6106b0652fcbb74ccdb5931c030dcf37734daf359657619' 
  AND token = 'XBJ5I1EdgdyVFEtdGRFkypd0fxpJcD5pJxteTsxEw1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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