SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7c3a699c14c235e7d5f9b38f05a9b3c27fa5fd2041ae036814d15156b83a455c' 
  AND token = 'c9R1WvV8Zco1wnkTVbaAGODcnddXQ83U32y47YZGang=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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