SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5baef12e79920c804dc4d88df08ac0fc286945bc4b264cf6dd7a40e171f3d6a' 
  AND token = 'SCh/NEhMej5+04cq1bpLUO4eDta3TsemC6esK7dKWsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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