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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cd6afc9a3a8f1761fc944b2e636a6a48dd2887d9a0d345a57a54fb0df05c03e5' 
  AND token = 'p3714oK7UHSRL6b2bwe3lc9mKTg+Rv8AppQad+3h9lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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