SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b2bc2bce4cf7cbe2ac065a0bb63bb84a2e9e0a77a2fe0149f9b52fabb4ce3567' 
  AND token = 'Uat4p9RyR2M0cF2i+k90wig/FQoQCTwttH46TDRs7/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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