SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bee40bb6a26ccd9265d07b85ca0333e8161bb0b24683e83abf112dce18344e91' 
  AND token = 'GWKpkNVcGK45qgczddlzm7yyq+IW4qrjzakewkryoVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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