SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '648f154a1e817e3f7f1f92ba81bf0a762111e8c4e644470007949b761e098331' 
  AND token = 'ZqbhLJWeuLVQjWvYDVajzjmJpB7KasWE6FeNPcNALTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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