SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3f7a76a3598c9fb14b11108f215f20727de3f77c8b9c3d44514bc75e9bc5257' 
  AND token = 'xQW584bWmcR5JYBTBVaymuC3RJ26KjWfzqbhvOeaP4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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