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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f8a304f1ddb36d0732eedbb34d017d6bb344235585698d48f9758cd45af799d4' 
  AND token = 'kXfxOHqp5OamiDww2yX9rlecxsvNYhQCpsQIK0Aecxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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