SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8865d6eb982ff296f86aba3ac2d9acd0535317d45af538b0d1175e7a96a164b' 
  AND token = 'NzUj1fdiBqSxuKZdYEe4Johygsbgtu7tJtzYAVSjYew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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